Sheet detector



Feb. 12, 1929. 1,701,861

H. c. NIBLACK SHEET DETECTOR Filed May 1'7, 1927 3 Sheets-Sheet 1 INVENTOR .ATTORNEY Feb. 12, 1929. 1,701,861

H. C. N-iBLACK SHEET DETECTOR I Filed May 17, 1927 5 Sheets-Sheet 2 INVENTOR fiBARTCMBLAC/f.

v l v ATTORNEY H. C. NIBLACK SHEET DETECTOR Feb. 12, 1929.

INVENTOR 1565 457- C 11/ 54/10/11 3 Sheets-Sheet 3 Filed May 17, 1927 ATTORNEY atente HOBART C. NTBLACK, OF ROCHESTER, NEW YORK,

N OFFICE.

ASSIGNOR 'IO HARRIS-SEYBOLD- SHEET DETECTOR.

Application filed. ma 17, 1927. Serial no. 192,022.

My invention relates to automaticsheet detectors used more particularly with paper feeders for printing presses, folders and like machines, and comprises certain improvements in mechanisms for automatically arresting the operation of the feeder in case two or more sheets are simultaneously fed forward by the sheet separating devices.

The objects of my invention are, among other things, to provide a sheet detector or caliper of this type which shall operate with greater certainty and effectiveness on the successive sheets advanced by the feeding devices, and particularly to rovide' a sheet detector which will not be a ected by small bits of paper pulp or other pieces of foreign matter that may be on the top surface of the sheets, but which will be immediately effective if more than one sheet of paper is simultaneously advanced by the paper feeder. A further object is to provide a new and improved sheet detector in which the successive sheets of paper will pass between two revolving rollers that are always moving with the sheet, but such detector will be actuated only by an abnormal thickness of paper (two sheets forwarded as one), and will permit small fragments of paper or pieces of foreign matter to go through the rollers. without jamming the sheet and with out causing the detector to work, since according to my improvement such fragments or pieces must be large enough to raise the upper roller for approximately a half-turn before this sheet detector maybe actuated to throw the feeder out of operation.

A further object is to provide an improved sheet detector of such construction and arrangement of its component parts as 4.0 to be exceptionally sensitive in operation with capabilities of adjustment to accommodate the detector mechanism for difi'erent kinds and-thicknesses of paper that is forwarded to the front guides preparatory to be seized by the grippers on the impression-cylinder of the press.

Other objects and advantages ofmy invention will be apparent from the following description thereof, and a preferred embodiment' is shown in the drawings in which- Fig. 1 is a side elevation of my sheet detector and tripping mechanism showing a single sheet of paper being advanced by the coacting rollers with the feeder trip latched;

Fig. 2 is a view similar to Fig. l except that two sheets of paper are passing through the rollers as one and the feeder trip is unlatched;

- Fig. 3 is a side elevation of my sheet detector attached to a printing-press with the sheet feeding device shown diagrammatically at the right;

Fig. 4 is a detail end view of the feed rollers and detector rolls with their associated parts; and

Fig. 5 is an enlarged detail view of th tri latch.

,gimilar numerals refer to similar parts throughout the several figures.

Referring to the drawings and more particularly'Fig. 3, the impression-cylinder- 6 carries the sheet grippers 7 actuated in the usual manner by the tumbler 8, spring arm 9 and spring 10 to take the successive sheets from the feed-board 11 after they have been advanced and alined against the front guides 12. The printing cylinder 13 forms the usual printing couple'with the impression cylinder 6. The shaft 14 of the cylinder f3 carries the sprocket 15 to drive the sprocket chain 16 in the direction shown by the arrow to actuate the feeding devices -hereinafter described. The drive chain 16 passes around the sprocket 1'1 loosely mounted on the hub 18 of the tape rolls 19 journalled on the tape roll shaft 20. The conveyor tapes 21 pass around the tape rolls 19 and 22 in the direction of the arrow to advance the sheets to the feed board 11 in the usual manner.

Keyed to the tape roll hub 18 is the gear.

23 which engages and drives the pinion 23 which in turn engages and drives the large gear 24 mounted on the cam-shaft 25. The

gear- 24 carries the crank pin 26 on which is pivoted the connecting link 27 pinned at 28 to the oscillatable sucker arm 29 carrying at its, lower end the sucker 30 arranged ust above the pile of sheets 31. The sucker 30 is connected to any source of exhaust air pressure by the hose 32. The cam 33 is keyed to the shaft 25 to raise and lower the arm 34:

to rock the shaft 35 suitably journalled in the side-frames 36 and 37 (Fig. 4).

Referring more particularly to Figs. 1, 2 and 4, the lower rollers 38 are mounted on the hub 18 of the tape rolls 19 and are driven in unison with such rolls. The arm 39 is journalled on the shaft 35 and is free to move independently of this shaft; the arm 39 carries the upper roller 40 j ournalled thereto and the bracket 41 is rigidly secured to the shaft 35 by the set-screw 42. Journalled to the bracket 41 is the. arm 43 which carries the roll 44- pinned thereto. The adjusting screw 45 passing through the bracket 41 and engaging the lug 46 on the arm 39 properly positions the roller 40 over the lower roller 38, the spring 47 coiled about the screw 45 between the bracket 41 and lug 46 allowing the arm 39 and roller 40 to be lifted independently of the movements of the bracket 41 and rock-shaft 35. The adjusting screw 48 passing through the head 49 on the bracket 41 with the screw point bearing on the arm 43 enables a proper positioning of the roll 44, the spring 50 coiled about the screw 48 permitting the arm 43 and roll 44 to be raised independently of the bnacket 41. The light spring 51 pinned to the arm 43 and roll 44 normally maintains the roll 44 in the Y position shown in Fig. 1.

The hub 52 of the roll 44 is of metal and has fastened thereto the semicircular piece 53 formed of fibre or other electrical insulating material. Suitably secured to the arm 43 are two insulating blocks 54 and 5 5 to which are secured the metallic brushes 56 and 57 respectively bearing on opposite sides of the rollhub 52 as shown in Figs. 1 and 2. The brush 56 is in electrical contact with the'battery 58 through the wire 59, while the wire 60 connects the brush 57 with the electro-magnet 61 fastened to the bracket 62 onthe side-frame 63; the wire 64 also connects the battery 58 with the magnet 61 to complete the circuit. Below the core' 65 of the magnet 61 is the steel bar 66 pivoted to the bracket 62, the bar 66 carrying the pivoted link 67 which is attached to the toggle lever 68 pivoted to the pawl 69 and pinned to the bracket 70 .on the side-frame 63. The bracket 70 supports the stub shaft 71 to which is secured the latch collar 72 and bell crank lever 73, the upper arm 74 of which lever 73 is actuated by the pull spring 75 connecting the lever arm 74 to the side fname 63. The lever 7 3 i s connected by the link 7 6 (Figs. 1, 2 and 3) with the trip handle 77 pivoted on the.

stub shaft 78 secured in the side frame 37. The forward hook-shaped end 79 (Fig. 5) of the handle 77 engages the tail end of the pawl 80 pinned to the arm 81 which is keyed to the end of tape roll shaft 20, and the onetooth ratchet wheel 82 is suitably fastened to the sprocket 17. In normal operation the pawl 80 is in locked engagement with the ratchet 82 whereby the sucker feeding mechanism and conveyor tapes 21 are operated to separate and then advance the successive sheets from the pile 31 to the press.

To set this improved sheet detector the upper roller 40 is adjustedby the adjusting screw 45 to just touchthe lower roller 38; then the roll 44 is adjusted by the screw 48 so that two thicknesses of the paper to be run from the pile 31 will be pinched between the roll 44 and roller 40 just enough to enable these gauging sheets to turn the roll 44 when pulling same from between the roller 40 and roll 44. Une or more of these sheet detectors may be efl'ectively used as required.

' In operation" when the large gear 24 is revolving the sucker arm 29'and sucker 30 are reciprocated back and forth over the pile 31. On the forward stroke the top sheet is carried between the rollers 38 and 40, the roller 40 being slightly raised by the cam 33 to admit the leading edge of the advancing sheet. When the sucker arm 29.

sition of the various parts are as shown in Figs. 1 and 3, andthe paper will not raise the roller 40 enough to. engage the roll 44, and the feeder will not be tripped. However should two sheets be advanced as one as shown in Fig. 2, the roller 40 engages the roll 44 and turns the latter to the position shown so that the insulating piece 53 will be turned so that both brushes 56 and'57 will contact with the metallic hub 52 thus closing the electrical circuit through the battery 58 by which the magnetic core 65 is energized to lift the'bar 66 and link 67 to break the toggle lever 68 thereby unlatching the collar 72. Such unlatching of the collar 72 will enable the spring 75 to pull the lever; arm 74 to the left (from Fig. 1 to Fig. 2

position) to rock the shaft 71 in an anticlockwise direction (Fig. 3) which movement at once'raises the trip handle 77 to disconnects the feeder and stops the forwarding of the sheets on the conveyor tapes 21.

It will be seen that my improved sheet detector will not wedge or jam the successive sheets and thereby waste stock since the rollers 38 and 40 are always moving with the sheet carried therebetween (Figs. 1 and 2), but when the roller 40 is raised by double feeding so that such roller 40 engages the detector roll 44 there is no slipping or scraping on the surface of the paper and small fragments or elevations on the surface of the sheet will not cause the detector to operate. The raising of the roller 40 must be continuous for at least two or three inches of the sheets travel before the roll 44 is rotated sutliciently to inaugurate the tripping of the feeder. t

I claim as my invention 1. In a sheet detector, means for advancing successive sheets, two coacting rollers between which the sheets are advanced, and means normally spaced from said rollers when single sheets are fed therebetween, but actuated by one of said rollers independently of the forward movement of the sheets when two or more sheets are fed for rendering said sheet-advancing means in active.

2. In a sheet detector, means for advancing successive sheets, two coacting rollers between which the sheets are advanced, and means comprising an idler roller normally spaced from the upper of said rollers when single sheets are fed therebetween, but actuated by the revolution of said idler roller when two or more sheets are fed for rendering said sheet-advancing means inactive.

3. In a sheet detector, means for advancing successive sheets a driven roller, an independently movable coacting roller between which the sheets are advanced by the driven roller whereby said coacting roller is rotated, and an idler roller normally spaced from said coacting roller when single sheets are fedtherebetween, but actuated by the revolution of said coacting roller when two or more sheets'are fed at one time for rendering said sheet-advancing means inactive.

4. In a sheet detector, means for advancing successive sheets, a driven roller, an independently movable coacting roller between which the sheets are advanced by the driven roller whereby said coacting roller is rotated, an idler roller normally spaced from said coacting roller when single sheets are fed therebetween, but actuated by the revolution of said coacting roller when two or more sheets are fed at one time for rendering said sheet-advancing means inactive, and means for adjusting the relative positions of said coacting roller and .idler roller to accommodate for diflerent thicknesses of sheets.

5. In a sheet detector, means for advanclng successive sheets, a driven roller, an independently movable coacting roller be-- tween which the sheets are advanced by the driven roller whereby said coact-ing roller 1s rotated, an idler roller normally spaced from said coacting roller when single sheets are fed therebetween, but actuated by the revolution of said coacting roller when two or'more sheets are fed at one time for rendering said sheet advancin means inactive, and separate means for a justing the relative positions of said coacting roller and idler roller to accommodate for difierent thicknesses of sheets. 1 t

6. In a sheet-detector, means for advancing successive sheets, two coacting rollers between which the sheets are advanced, a tripping mechanism throwing, said sheetadvancing means out of operation, and means normally spaced from the upper of said rollers when single sheets are fed therebetween, but actuated by the revolution of said upper roller when two or more sheets are fed at one time for inaugurating the action of said tripping mechanism.

7. In a plural sheet detector, means rotatable in the path of the sheet being advanced thereby and a detector member out of contact with the sheets but actuated by the revolution of said means when two or more sheets are advanced simultaneously for rendering the sheet-advancing means inactive.

8. In a plural sheet detector, coacting rollers rotated by thesheet being advanced thereby and a detector member out of contact with the sheets but actuated by the partial revolution of one of said rollers when two or more sheets are advanced simultaneously for rendering the sheet-advancing means inactive.

9. In a plural sheet detector, means for advancing successive sheets, coacting rollers rotated by the sheet being advanced thereby, a tripping mechanism throwing said sheet advancing means out of'operation, and

a detector roller actuated by the partial rev-' olution of one of said coacting rollers when two or more sheets are advanced simulta-- thereby, a detector roller actuated by one of said rollers when two or more sheets are advanced simultaneously for rendering the sheet advancing means inactive, and means for adjusting said detector roller relatively to the other rollers,

12. In a plural sheet detector, means rotatable in the path of the sheet being ad-.

vanced thereby and a detector member out of contact with the sheets but rotated to a predetermined extent by the revolution of said means when two or more sheets are admonaei neously for rendering the sheet-advancing means inactive.

14:. In a plural sheet detector, means rotatable in the path of the sheet advanced thereby, an electromagnetic trip mechanism throwing the sheet advancing mechanism out of operation, and an electric contact device comprising a detector roller partially rotated by said means when two or more sheets are advanced simultaneously for bringingsaid detector roller in circuit with said electromagnetic trip mechanism.

HOBART G. NIBLACK. 

